What is the difference between combustible and flammable material ? Eg: Ammonia is combustible not flammable.?

Question

Ammonia is an inorganic compound and not a fuel. It is a noncarbonious material. It combines with air and forms explsive mixture when the composition of ammonia in air is between 16 and 25%. Ammonia is in vapour form at 1 atmospheric pressure and temperature above minus 33 degree celcius.

Answer 1

From a "Dangerous Goods" standpoint :

Flammable materials have a flash point below 61°C. So, most common solvents (Stoddard solvent, kerosine, petrol, VM&P Naptha) and organic liquids and gases (acetone, ether, nitromethane, methane, ethane, propane, butane, ... up to about nonane) are flammable. Some solids (eg naphthalene) are also flammable.

Combustible materials have a flash point greater than 61°C. So diesel fuel, paper, coal, wood, etc are all combustible.

Also, don't get confused between explosivity and flammability - many explosives aren't flammable. C4 is an example - it will burn (combust) but requires percussive detonation to make it explode. So here's a tip - don't try to "stamp out" burning C4!

Also, explosivity may be limited to a certain range of concentrations (expressed as Lower Explosive Limit - LEL and Upper Explosive Limit - UEL). These are usually expressed as the % w/v of the fuel in air, although it is sometimes expressed in relation to the oxygen content.

Answer 2

Combustible Vs Flammable

Answer 3

Flammable Vs Combustible

Answer 4

Combustible materials can explode all at once with an ignition source. Flammmable materials will burn rather than explode. Almost any dry powder that forms a dust can be combustible. Explosions frequently occurred in flour mills, even though flour does not burn.

Maybe another way of looking at it is:

combustible - burns all at once, and produces an explosion

flammable - burns, but at a steady rate

Answer 5

Combustibles are is capable of releasing energy when its chemical structure is changed or converted. This energy does not necessarily have to be released by fire. In your example, ammonia releases its energy when 16 to 25% of it combines with air.

Materials that will ignite at temperatures commonly encountered are considered flammable. Ammonia cannot catch on fire just by encountering room temperature or 120 degree weather. So therefore, it is not flammable.

Answer 6

Combustion is a more rapid form of oxidation than is fire. So, combustible materials more readily combine with oxygen than mere flammable materials.

Answer 7

The difference between combustible and flammable materials is that combustible materials combust and flammable materials flamm. I thank you.

Answer 8

combustible will burst into flames, flammable will burn when lit